The rectangular groove is the standard version of an O-ring installation space. It is inserted into the inner or outer part of the sealing system in a piston or rod seal. The base of the groove forms a sealing surface.
When installed, the O-ring sits in the groove and is pressed between the groove base and the surface of the second component. Despite the designation as a rectangular groove, the groove flanks can also be at an angle of 95 degrees to the groove base.
The rectangular groove also serves as an installation space for flange gaskets. Here, however, it does not run radially but axially.